1. Field of the Invention
The present invention relates to an image display system capable of displaying an image on the right and left eyes of a viewer.
2. Related Art Statement
Such a system for displaying an image on the right and left eyes of a viewer has been disclosed in, for example, Japanese Patent Opened No. 26,289/92.
The construction of such an image display system described in Japanese Patent Opened No. 26,289/92 is shown in FIG. 10. In this system, use is made of one liquid crystal display (hereinafter referred to as an LCD) 50 as an image displaying element. An image (pencil of rays) displayed on the LCD 50 is incident on a half-mirror 55 through a lens 51, mirrors 52, 53 and a lens 54. Then in the right eye system, on the one hand, the pencil of rays is reflected by the half-mirror 55 and reaches the right eye through mirrors 56, a lens 57, a mirror 58, a lens 59 and a mirror 60, and in the left eye system, on the other hand, the pencil of rays is transmitted through the half-mirror 55 and reaches the left eye through mirrors 61, 62, a lens 63, a mirror 64, a lens 65, and a mirror 66.
In the above conventional image display system, use is made of an LCD placed at the position in front of and deviated from the eyes as an image display system. The image displayed on the LCD is split into two portions for right and left eyes by the half-mirror and led to both eyes of the viewer, so that it is necessary to provide a common light path for right and left paths and splitting light paths after the half-mirror as well as to provide a large number of optical elements such as lens and mirrors or the like in the respective light paths so as not to invert the image. Moreover, a part of the light path is superimposed so that the light system becomes complicated and thus to overall system becomes large, of resulting in an increase of weight. Such a conventional image display system is, therefore, not suitable as an image display system worn on the head.
The image display system for displaying a magnified image has been disclosed in, for example, Japanese Patent Opened No. 191,389/91.
The construction of such an image display system described in Japanese Patent Opened No. 191,389/91 is shown in FIG. 11.
Such an image display system comprises a display section 71, a half-mirror 72 and a magnifying mirror 73. The display section 71 displays the contents of the image information outputted from the image information output means of a computer (not shown) or the like. The display section 71 is provided on the upper portion of a housing 77 constituting the outline of a shell of the display system, so as to direct the display surface of the display section downward. The magnifying mirror 73 is placed under the housing 77 in such a manner that the reflection surface of the mirror 73 is opposite to the display surface of the display section. The magnifying mirror 73 is bent along two axes in such a manner that a magnified image 75 of the image displayed on the display surface of the display section 71 and obtained by the construction shown in FIG. 12 is magnified uniformly in all directions. The half-mirror 72 is placed between the display section 1 and the magnifying mirror 73 with an inclination of 45.degree. to its display surface.
In this case, the optical axis of the magnifying mirror 73 passes through the center of the half-mirror 72 and the center of the display section 71 perpendicular to the display surface of the display section 71. The dimensions of the magnifying mirror 73 and the half-mirror 72 are set in such a manner that the image displayed on the display section 71 can be reflected without discontinuation. According to such construction of the display system, a part of the light emanating from the display section 1 is transmitted through the half-mirror 72, and reflected by the magnifying mirror 73 and then again returned to the half-mirror 72. A part of the light incident on the half-mirror 72 is reflected by the half-mirror 72 in one direction perpendicular to the optical axis of the magnifying mirror 73 and reaches the eye of an operator 74. A part of the light emanating in the above one direction from an object 76 in the background present in the other direction perpendicular to the optical axis of the magnifying mirror 73 is transmitted through the half-mirror 72 and reaches the eye of the operator 74.
At a side surface of the housing 77 in the above one direction, a light transmission opening 77a for passing through the pencil of rays emanating from the half-mirror 72 to the operator 74 is provided. While at a side surface of the housing 77 opposite to the light transmission opening 77a, a light transmission opening 77b for passing through the pencil of rays emanated from the object 76 present in the background to the half-mirror 72 is provided.
Such a conventional image display system is constituted to be able to observe the images on the display surface and the background, simultaneously, so that it is completely different in construction from the image display system wearable on the head.